The present invention relates to a logic circuit module and a semiconductor integrated circuit having a recording medium storing the module, and more particularly to a semiconductor integrated circuit having a function of controlling a power consumption of another semiconductor integrated circuit.
An example of a conventional method of lowering a power consumption of a semiconductor integrated circuit is described in JP-A-07-20968. With this method, the consumption power of a computer is reduced by dynamically changing the operating voltage and frequency. Namely, by dynamically lowering the operating voltage and clock speed, the power consumption of the computer system is reduced.
An example of an interface to the external is described in JP-A-06-202753 entitled “Method of Stopping Clocks of Computer System and Processor”. A clock control signal input is provided in an external interface of a logic circuit. By inputting a signal to the external interface, clocks of a CPU can be stopped at any time irrespective of an instruction currently executed by the processor, while the defined status of the processor is ensured.
In “Integrated Circuit and Computer System” disclosed in JP-A-2000-132263, a common monitor clock is used for different modules in each integrated circuit and the total power consumption is reduced by a combination of an active power-down control and a passive power-down control.
The above-described conventional methods do not provide, however, sufficient consideration of a system LSI constituted of a combination of a plurality of reusable logic circuit modules (IP cores: IP is an acronym for Intellectual Property). Generally, in configuring a system LSI from a combination of IP cores, which IP cores are to be disposed in the system LSI is not still decided at the time of design (FIG. 22). Although the above-described conventional methods describe the technique of a power voltage control to control a power consumption, they do not disclose a method of changing the power voltage of only some circuit modules of a system LSI.